Brake



Aug. 30, 1927.

H. C. HEATON BRAK E Filed April 8. 1921 2 Sheets-Sheet l Z 6 a 1 w 5 7 w wfifi 3 5 2 W 2 |a|y1li 1 11 I 7 a w 192! H. c. HEATON BRAKE 2 Sheets-Sheet 2 Filed April 8, 1921 Patented Aug. 30, 1927.

,UNITED' STATES PATENT OFFICE.

minunr c. m'ron, or name, rumors.

mun.

Application filed April a, 1921-. Serial in. 459,570.

My invention relates to braking devices, and more specifically to an improved fluid pressure braking device especially adapted or'use on motor vehicles.

The mechanical transmission to the mechanically operated brakes, at present commonl employed. on motor vehicles, is objectiona le in many respects. It requiresalarge number of different parts, and relatively complicated. mechanism for increasing the force applied by the Operator to a force suflicient to contract or expand the brake band and hold the wheel stationary. The ielding and wear of the pivotal supports, which are subjected to very heavy loads, necessitates frequent readjustment of the brake; relatively heavy coil springs are usually necessary to slack off the brakes. All the moving parts employed lie under the body of 0 the car, where they are apt to be broken in travelling over rough roads, and where they become coated with dirt, and are difficult to get at for adjustment or repair.

The chief ob'ect of my invention is to eliminate the a ove mentioned undesirable characteristics by providing fluid pressure means for a plying the brake.

Another object is to provide a very simple fluid pressure bra-king mechanism, durable in service cheap to manufacture and easy to assemb e.

Another object is to provide power means for ap lyin the brake.

Anot er 0 ject is to provide power means for applying a constant braking force, and means controlled by the operator for varying the force. V v

urther objects and advantages of my in-' vention will become apparent as the description proceeds.

- In the accompanying drawin s:

Figure 1 is a fragmenta si e view of a runmng gearof an automo ile, illustrating in a. diagrammatical way the application of a device constructed according'to my invention thereto.

Figure 2 is a section through one of the rear wheels of the motor vehicle illustrated in Figure 1, showing the construction of the braking mechanism proper.

Figure 3 is a much. more enlarged section,

showm in greater detail the mounting of some 0 the parts illustrated in Figure 2.

Figure 4 1s a section through a suitable pressure supply means; and,

'spacingbetween the plates 28 and force the Figure 5 is an enlarged section through the piston of the same.

Figure 6 is a diagrammatic showing of another device operating by diflerences of gas pressure, and

Figure 7 illustrates another means of obtaining pressure differences to operate the brakes.

In theembodiment of my invention select: ed for illustration, the rear wheels 10 are mounted on the running gear 12 in any suitable or preferred manner, and power is transmitted to them through live axles 14 from the power plant 15 by any of the transmission mechanisms well known in the art. -70 As the above mentioned devices are well known, and per se form no part of the present invention, a detailed description of the same is deemed unnecessary.

The wheel 1.0 is rotatabl mounted on the stationary axle 16 by suita 16 means, such as be arranged to grip the outsides of the drum '22. A cover plate 24, fastened in place by bolts 26, completes-the enclosure, and the cover plate and drum provide opposed annular friction surfaces, with radial faces. The braking element hereinafter to be described may expand to cause friction and retard the rotation of the wheel 10 with respect to the axle 16.

Between the casing and the cover are stationary plates 28 s lined to the stationary axle 16 as at 29. uitable friction facings 30 are carried by the plates 28.

The hydraulic means provided for expanding the plates 28 to apply the brake comprises, in this instance, a thin flat annulus 32, in the nature of a diaphragm adapted to receive pressure fluid between its walls, and by its increase in thickness to increase the facings 30 into frictional engagement with 1 the drum 22 and cover 24. The resilience of the walls of the annulus 32 is preferably sufficient-to cause it to contract when the inside ressure is reduced, and the plates 28 are suitably attached to the annulus as by rivets 33, to positively withdraw the plates and prevent the brakes from dragging. Preferably a spring 61 raises the plunger .46 to create a drop in pressure, so that the atmos pheric pressure will slack off the brakes.- 110 vided to hold the annulus 32 in correct axial position with respect to axle 16.

The pressure fluid may be delivered to the diaphragm 32 on each wheel, by means of a tube 42 communicating therewith. I have illustrated a suitable means actuated by the operator for varying the fluid pressure in tubes 42 and diaphragm 32 to apply the brakes.

Referring to Figure 4, the cylinder 44 receives the piston 46 carried by the piston rod 48 pill'ojecting through the cylinder head 50, pac mg 52 and pac 'n nut 54, and carries at its upper end a suita le shoe or pedal 56, for engagement by the foot of the operator. The piston 46 is preferably provided with a small s ring-held check-valve 58, permitting flui to enter the cylinder, but not to leave it.

In the operation of the improved device disclosed, the diaphragm and connecting tubes and the cylinder below the piston 46 are all completely filled with a relatively incompressible fluid, preferably oil. A small amount of oil is placed in the cylinder above iston 46, and cap 50 is then permanently astened in place by means of bolts 60. Since a the device is practically hermetically sealed, it will be obvious that when the parts are properly adjusted, no readjustment will ever be necessary. Any slight leakage that may occur past. piston 46 may be quickly and easily compensated for by pulling up on the shoe 56 to permit the oil above the piston to flow back into place through the check valve 58. It should be noticed that the only connection between the completely housed and protected piston 46, and the completely housed and protected brake diaphragm 32 is the small tube 42, which may be placed in any desired position out of the way, for instance, inside the channels forming the main frame of the chassis. An important feature of the invention resides in the equalizing effect of the liquid, whereby even application of the brakes is assured.

The conduit 42 may obviously be rolonged, as at 62 (see Figure 1) to dellver pressure fluid to actuate any suitable semaphore or signaling device 64 at the rear end of the car. In this way the use of the brakes to slow down will be automatically indicated to those in the rear. The same support may obviously be used as a mounting for any well known type of direction signaling means also.

In Figure 6 I have indicated a. pump 66 driven by the engine, and means for controlling the delivery of compressed gas to a suitable cylinder 68 to actuate a piston 70 0pv eratively connected to a brake lever 72 for operating a brake of an well known construction. The pressure uid from the pump is preferabl stored in a tank 74, a safety valve7 6 being provided to prevent the development of excessive pressure in the tank. The application of the brake may be controlled by means of a foot pedal 78 similar "to those now customarily employed, and op-.

eratively connected to a three-way valve comprising a casing 80 and .a valve member "82. In the position illustrated in Figure 6,

the brake is not applied, passageway 84 in the valve member connecting chamber 86 with the atmosphere through passageway 88. It will be apparent that depressing the pedal 78 will rotate passageway 84 into register with assageway 90 connected to the tank, where y pressure fluid will be delivered to the chamber 86 and through conduit 92 to the cylinder 68 to apply the brake. Passage- Ways 88 and 90 are preferably spaced apart so that an intermediate position is provided in which passageway 84 is cut oif from communication with either. This makes it possible for the operator to permit a certain pressure to be built up in cylinder 68, and

then by moving pedal 78, to shift the valve to the intermediate position, whereby the braking effort already obtained will be maintained indefinitely as long as the edal 78 is held in the lntermediate posi on. spring 94 is preferably provided for relieving the brake elements as soon as passageway 84 is moved into register with passageway 88.

It will be obvious that pump 66, tank 74 and valve 82 ma be employed for the control of the dia ragm brake illustrated in Figure 3 mere y by connecting conduit 92 thereto.

In Figure 7 I have illustrated vacuum storage means in the nature of a storage tank 96 connected to the inlet manifold 98, a check valve 100 being provided adjacent the manifold. It will be obvious that tank 96 may be connected to passageway 90, shown in Figure 6, to form an operatlve arran ement, except that spring 162 must act in t e opposite direction from spring 24. The high suction necessary to prevent the engine from racing whenever it is not operating under a load will exhaust tank 96 and maintain a suitable reserve of power for operation of the brake. It will also be obvious that the signaling device 64 may readily be connected to either of the systems illustrated in Figures 6 and 7.

Without further elaboration, the foregoing will so fully explain the gist of my mvention, that others may, by applying current knowledge, readilyadapt the same for use under various conditions of service, without departing from certain features properly constituting the essential items of novelty involved, which itemsare intended 'to be defined and secured tome lowing claims.

I claim:

1. In combination, a fixed axle, a wheel rotatably journaled upon said axle, said wheel having a pair of spaced brake surfaces rotatable therewith, a pair of spaced brake shoes interposed between said brake surfaces, said brake shoes extending inwardly to the fixed axle and secured directly thereto against rotation with the wheel, the connection between said shoes and the fixed axle being removed from the sides .of the shoes and disposed adjacent the axis of the wheel said connection permittin sliding of sai shoes with respect to the ient diaphragm between said brake shoes and means for forcing liquid into said diaphragm to expand same and force said shoes apart in opposite directions and into frictional engagement with the rotatable brake surface on the wheel for the purpose of braking rotation of the wheel.

2. In a device of the class described, a fixed axle, an annular casin rotatable with respect to said axle, a fi-xed ange carried by said axle, fluid pressure means inside said casing for exerting a braking-effect thereon, and a stationary conduit extending through said fixed flan e for conveying ressure fluid to said flui pressure means, sai casing having two face (plates extending in close to the axle to provi e two opposed radial braking surfaces. s

3. In a device of the class described, in combination, a cylinder opening at one end to a hermetically sealed receiver, a piston in said cylinder, a iston rod entering in said cylinder from t e other end, and a check valve in said piston opening toward the receiver end of the cylinder.

4., In a fluid pressure braking system, a

by the fol-- ed axle, a resilsystem hermetically sealed at all points except one, mechanical means entering the system at said point to, develop fluid pressure therein, and means for preventing the development of pressure on the entry side of said mechanical means b said last means.

5, In combination wit having a fixed rear axle, a live axle in said fixed axle, and a wheel rotatably mounted on said fixed axle and driven b said live axle,

with said wheel, 7

annular lates rotatin annular p ates axially s idable but not rotatable on said fixed axle, a resilient annular dia hragm between the slates on said axle, and means for forcing uid into said diato ex and the same and force said fplates into frictional ene plates carried by end phra axial y slidab e gagement with t wheel.

6. In a liquid-braking means, in combination, a system hermetically sealed at all points except one, a piston at the unsealed point for applying pressure to' the system, means biasing said piston to a predetermined initial equilibrium position, a check valve in said piston openin into the system and an additional li uid c arge above sai iston for sealin sai check va ve and entermg the system t rough thesame to replace losses by differential thermal contraction or by leakage around the piston.

7. In a liquid-braking means, in combination, a liquid-filled system, a piston for applying pressure thereto, an inwardly opening check valve in the piston, and a replacement charge of liquid covering the in st to said check valve to seal the system against entry of gas.

In witness whereof, I hereunto subscribe my name, this 2nd day of April, A. D. 1921.

HERMAN o. HEATQN.

a motor vehicle 

